Short-term polystyrene nanoplastic exposure alters zebrafish male and female germline and reproductive outcomes, unveiling pollutant-impacted molecular pathways

12 pages, 6 figures, supplementary material https://doi.org/10.1016/j.jhazmat.2024.136529.-- Data availability: RNA-sequencing data generated during this study can be found at NCBI Gene Expression Omnibus (GEO) under accession number GSE279916

Nanoplastics pollution is a rising environmental concern whose impacts on biodiversity and human health are far from being understood. This is particularly salient in aquatic ecosystems, where the majority of species depend on external fertilization for reproduction. Here we evaluated the effects of a short-term exposure to engineered polystyrene nanoplastics (NPs) in the zebrafish germline to further explore their impact on reproduction. To this end, zebrafish (Danio rerio) were exposed to 5 mg/L of 45 nm polystyrene (PS)-NPs via water for 96 h. We show that, in males, nanoplastics induced testicular histological alterations with abnormal sperm clustering and chromatin compaction, resulting in viable spermatozoa but with reduced motility. Moreover, in females we observed an alteration in oocyte stages frequencies during oogenesis, possibly reflecting alterations in oocyte growth. RNA-sequencing analysis in male testis links nanoplastic induced alterations in the expression of genes involved in chromatin structure, meiosis and DNA double-strand break formation and repair progression, and gametes recognition. Flow cytometry analysis revealed that the observed effects in males were directly due to nanoplastics penetrating the testicular barrier and being internalized within germline cells. Overall, our results demonstrate that acute exposure to NPs can compromise reproductive fitness, underscoring the environmental and health impacts of NPs pollution

This work was supported by the Spanish Ministry of Science and Innovation (PID2020-112557GB-I00 founded by AEI/10.13039/501100011033 to A.R.-H.; PID2021-126710OB-C21 to N.R.A; and PID2022-138066OB-I00 to J.C. and PID2020-113221RB-I00 to M.T), the Agència de Gestió d′Ajuts Universitaris i de Recerca, AGAUR (2021SGR00122 to A.R.-H. and 2021SGR00068 to J.C) and the Catalan Institution for Research and Advanced Studies (ICREA) to A.R.-H. G.P. and L.A.-G. were supported by FPI predoctoral fellowships from the Ministry of Economy and Competitiveness (PRE-C-2021–0083 and PRE-2018–083257, respectively). L.M.-G. was supported by an FPU predoctoral fellowship from the Ministry of Science, Innovation and University (FPU18/03867). MT was supported by a Ramon y Cajal contract (ref. RYC2019–026841-I)

With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Peer reviewed